1. Field of the Invention
This invention relates generally to suspended pipe rack apparatus, and more particularly to a method and apparatus for suspending a pipe rack from vertical shafts without passing the assembly over the ends of the shafts.
2. Brief Description of the Prior Art
Architectural improvements and additions are constantly made in commercial and industrial buildings. One of the common problems encountered in changing the architectural construction is the removal or addition of suspended pipe racks. The pipe rack is a system of horizontally spaced channels suspended from the ceiling on a plurality of vertical threaded bars. The channel has a plurality holes through which the vertical rods are received as the channel is raised to the proper elevation. A washer and threaded nut is run up on the rod to engage the bottom of the channel and support the channel on the rod. Pipes and electrical cables are supported horizontally on the pipe rack channels and run horizontally overhead throughout the building.
When architectural improvements, additions, or changes require new pipe or electrical hook-ups or re-routing, the suspended pipes or electrical cables must be removed or replaced, or new ones added. This procedure often requires expensive periods of shut-down while the pipe racks are disassembled. In some cases, a second layer or intermediate pipe rack may be installed above the existing one to allow placement of the new pipe or cable before the old ones are removed.
To install an intermediate pipe rack above an existing one, it is necessary to remove the old channel from the vertical threaded rod, or to back off the nut and lower the channel. The intermediate channel must then be forced over the existing pipe and cable which often requires bending or cutting existing support rods to allow the intermediate channel to fit on the rods above the pipe and cable and then the old lower channel must be put back into position. The threading procedure alone takes many hours.
It would therefore be desirable to provide a method and apparatus for suspending pipe racks without the necessity of removing any members already in place utilizing interlocking channels and split nuts. Split nut devices are known in the art. There are several patents which disclose various split nut constructions.
Uhlig, U.S. Pat. No. 4,132,146 discloses a pivotally interconnected split nut.
Rovinsky et al, U.S. Pat. No. 4,462,731 discloses a split nut assembly wherein the nut is divided into two separate equal parts, and a hollow shell which is also equally divided. The parts are assembled with the parting lines offset by 90.degree..
Resnicow, U.S. Pat. No. 4,556,352 discloses a split nut having a snap lock configuration.
Resnicow, U.S. Pat. No. 4,274,323 discloses a split nut having interlocking pieces and also with an end washer feature.
Wrensch, U.S. Pat. No. 663,208 discloses a split nut which is hinged at one end and the jaws are secured together with a screw.
Shaffrey, U.S. Pat. No. 2,377,581 discloses a divided or split nut in four pieces.
Hindman, U.S. Pat. No. 3,038,366 discloses a split nut which is secured together by a wire clip.
German Pat. No. 1,144,542 discloses a split nut wherein the two halves have an arcuate tongue configuration.
English Pat. No. 455,165 discloses split nut having a dove tail tongue and groove interlock which slides together.
The present invention is distinguished over the prior art in general, and these patents in particular by a method and apparatus for suspending a pipe rack assembly from one or more vertical threaded shafts without passing the assembly over the ends of the shafts which utilizes vertically opposed U-shaped channel members each having a plurality of transverse slots extending transversely inward from opposite side walls that are placed laterally on the shafts then slidably received one on the other and secured in the overlapped position with threaded fasteners. The vertically spaced slots in the upper and lower channel members form a circular opening which surrounds the shaft. The assembled channels are supported on the shafts by split nut members having two separable internally threaded segments which encircle the shaft and are releasably joined together on the shafts as a single unit to engage the bottom surface of the lower channel member. The split nuts allow adjustment and leveling of the assembled channel members at the proper height. The channel assemblies form a plurality of generally parallel spaced channel assemblies capable of receiving and supporting pipes, cables, and the like thereon. The channel members may be installed above existing pipe racks on the same supporting shafts without the necessity of removing existing pipe racks.